I have a 57 olds 98 convertible and finally got it to the point where I can drive around my neighborhood. Pretty big milestone. I am a total novice, but the engine gets really hot. After I drove it for a couple minutes I noticed when I shut it off in my driveway I could hear the gas boiling out of the center carb.

being that I know nothing about old cars is this normal? It’s like 85-90 degrees out so I’m sure that may have a little to do with it. Or is this like the 4 wheel drum brakes and I need to manage expectations?

it’s a J2. Rebuilt all the carbs and set up per manual. Timing is at 5 degrees btdc.

Any help would be appreciated.

 

Congrats on getting it running.

Running hot is subjective, try to get an infrared/IR point-and-shoot thermometer to get some precise temp #'s. Do both heater hoses get hot? If not that points toward air in the system, low coolant or a stuck closed thermostat and if the car has sat forever rotted vanes on the water pump but the latter is quite rare.

About the center carb boiling gas, it doesn't sound normal to me but will defer to those with J2 expertise.

Good luck and post pics!!!​​​​​

 

ill get some temps and post pics. She’s been through a lot. I should write a book on the ordeal.

 

We have a forum for that...

 

ill post on it once I get some pictures.

 

57's suffer from the same issues as most all mid fifties cars have and that is vapor lock condition do to the alcohol based fuel we are forced to use in most areas. As a test insulate your gas lines with foam pipe insulation and see if you can hear the boiling fuel after a hard up hill run. Mine will boil fuel if I let it set for a few minutes after a heat soak then take off again only to spit and sputter till the gas in the lines cools down.. In more modern cars the gas is re circulated back into the gas tank and this problem is less noticeable or doesn't happen.....Tedd

 

I never have had a vapor lock on my 54 but then I have an electric fuel pump.

 

thanks Tedd. I’ll try insulating, but it sounds like it’s boiling in the bowl. I didn’t have any issues with the vehicle running. Just noticed it after I shut it off in my driveway. One thing worth mentioning is my water valve for the heater core is missing the diaphragm and lever to open the heater valve. I have the parts to install. Would that be part of the problem?

 

Shouldn't overheat without coolant flowing through the heater core. When another part of the cooling system e.g., radiator, thermostat or general clogging, turning on the heater/opening the valve will "band-aid" or be a crutch to aid in heat loss.

Heat is often turned on to assist the cooling system in overheat situations but shouldn't be needed.

Don't run more than 50% coolant, it reduces heat transfer.

Good luck!!!

 

I think the gas is just getting to warm/hot on it's way to the carb. I have a 1/2 inch insulating carb base gasket that helps a lot also. I believe it is aftermarket but you have 2gc carbs and I don't remember see any of these for the two barrels but I wasn't looking either.

If it becomes a issue(probably won't in the winter) try the pipe insulating stuff and see if that fixes the problem, then address it farther if you still have the issue. I haven't tries this but you might insulate the gas line from the tank to the fuel pump and get the ugly insulation out of sight if you show this car and you should..... Tedd

 

thanks Tedd, I’ll give the insulation a shot. I’m all reality I’m not going to be driving it in the winter.




here’s my car by the way.

 

......Just a thought. Have you checked the hear riser valve to make sure its free and opening ?

 

The car doesn't have a heat riser valve installed. One of many things that need to be added.

 

Just curious. Have you crawled under there and open the petcocks on both sides of the block? Full of rust and clogged?

 

Are you talking about the ones at the bottom of the radiator? If not I apologize I’m not sure what petcocks you’re referring to

 

No. There are two on the engine block sides. One on each side at the lower part of the block and near the middle. They are where the oil pan lip is. Sometimes they will have a petcock to to open or there will be two pipe plugs that have to be removed. Mine was doing similar to your when i picked it up a few months ago. I flushed the radiator quite a few times and also opened those petcocks on the block and had to shove a piece of welding rod in there to break the clogged up rust. I left them and drained it and the filled the radiator agin and left them open and ran the engine for a while. Left a nice rusty trail down my driveway. Did this more than once over about a three week period but now it seems much better. When i thought it was good, i filled it with 50/50 water and coolant.

 

wow I had no idea. I’ll have to go under and take a look. I’ll report back what I find. Thank you so much.

 

If you have trouble locating them, i have another running motor on a dolly and perhaps i can take a picture for you.

 

Let me see if I can find them first. Might be in the shop manual somewhere also. Appreciate your help

 

One more thing. If they are pipe plugs and not petcocks, then get a good bite on them with a socket or possible vice grips, if they have been buggered up before. I good grip on them helps to get them out. If i recall they are 1/4 pipe thread. Good luck, looking forward to your reply. And i think it was already posted, but how is the thermostat? My car sat for forty years and when i removed the thermostat housing, it looked like a rusty hardened wad of crap laying in there. I had to remove the chunks very carefully as it jus broke apart trying to remove it. Then i ran a flexible magnet around in side as far i could push it and kept pulling out rusty particles and crap. I have no thermostat in mine now.

 

im not even sure where the thermostat is, but I’ll take a look.

 

Just follow the upper radiator hose down to where it attaches to the top of the engine. Thats the housing with two bolts holding it on and the thermostat is inside it when you remove it.

 

gotcha. I’ll look. Thanks so much.

 

Before you go and start replacing parts and/or trying to fix something that ain't broke, you need to find out what the actual engine running temp is.

 

hi all, so I drove her around for 5-10 min and then measured the temp. The intake manifold below the center carb was reading around 213. Around 180 around the rest of the manifold.

is there a better place to point the infrared gun at besides the intake manifold? What’s a normal temp?

 

If your rad coolant is boiling, it might need a new rad cap. 13 or 15 lbs.

 

i don’t think it is, but I’m going to replace it to be on the safe side.

 

Looks like you are getting good advice. Doesn't sound like it's overheating but you can check the water flow thru radiator by removing the radiator cap when engine is cold. Then start it up and you should be able to tell when the thermostat opens and see the coolant flowing. If you have a old style thermometer you can monitor coolant temperature by setting in radiator cap opening. May need to use non ethanol fuel when it is very warm out, if available in your area.

 

I don't think you are overheating, what does your temp gage read does it spit out the overflow tube after shut off. And keep in mind your radiator came out with a 7 lb cap and is probably 60 years old be carful of putting a 15 lb cap on it. It may not need it or take the added pressure, why not fix or find one issue at a time. I like the ones that cost the least or the less risk.

Many a first generation Old's engines are running around without heat risers or stuck open ones with no issues except in winter cold. I would worry last about that right now....Tedd

 

Redd I think the worry about the heat riser is it being stuck in the closed position.

 

I'm not an expert on those generation engines by any stretch but those temps look good.

General question...What coolant ratio are you running? More coolant/anti-freeze than necessary reduces the cooling systems ability to rid heat. No less than 30% coolant for corrosion, no more than 50% for freeze protection to -34°F.

Your car looks awesome!

 

I don't think those temp readings are a problem. But they gas boiling in the carb? Even on an 85-90 degree day, i don't get that.